Slow Motion Rowing

Head of the Cam 2025 wrap up

Andy Southgate — Thu, 01 May 2025 20:20:06 GMT

First, the content! Videos!

Also, new for this time around, photos! There were no major disasters, although the photos from div 3 are a bit on the dark side. The photos come from a fixed camera bolted to the side of the tripod and I don’t touch it during the racing. It turns out that, yes, the camera will automatically take a photo every second, using its internal Interval Shooting feature, but what it won’t do is adjust the focus or exposure as it goes along. So that’ll need a bit more thought for next time. It does make the Flickr slideshows look cool though.

The camera set up for the Head of the Cam

The new video camera worked well, it’s a refurbished original Sony α1 that was going cheap (ish) now that the α1 II is out. Like last year, I’m recording 4k at 120fps and processing to 60fps at 1/8 speed, with Twixtor generating intermediate frames to keep it all looking smooth. There was a firmware upgrade to the lens too around the autofocus, and I think it’s holding onto the crews better, although still losing them at longer distance. I’ll change my focus area next time (was Wide, should probably be a Zone over the upper and middle screen) to see if it helps.

I also had to colour correct this time, as the camera didn’t get it right for division 2, probably due to the wrong settings. Anyway, I’ve discovered Lumetri Scopes now and there’s no going back.

The May Bumps is next, although I’m only here for the Wednesday and will then be away for a week. So I’m hoping for good weather!

The Head of the Cam 2025

Andy Southgate — Sat, 26 Apr 2025 20:30:58 GMT

Recording went well! With over 350GB of data pulled from the cameras, there’s a lot to work with. The good news is that I’ve got all of the crews that raced, the editing work for division 1 is done, and the over-engineered processing pipeline has sprung into life!

Some would say that a processing dashboard with live updates is unnecessary, but meh

The footage will appear on this YouTube playlist, over the next few days.

The livestream results were decidedly sketchy BTW. The first division was OK, but then the uplink bandwidth from my phones disappeared. Needs more work™.

Creating slow motion from normal video, with the new Twixtor app

Andy Southgate — Sun, 20 Apr 2025 06:57:22 GMT

Twixtor is software that turns normal-speed footage into slow-motion, using optical flow and, nowadays, discrete neural network (DNN) techniques. I’ve been using it since 2011, and here’s an example from back then. The video above was recorded at 50 fps, Twixtor generated an extra frame between each of the original frames, and it replays at 25 fps, giving a nice 4x slowdown.

The good news is that Twixtor is now available as a standalone app and is cheaper than the plugin version. If you want to slow-mo your normal-mo, it’s worth a look.

Here’s the same rowing video on YouTube, with the rest of the division. It was the wettest day I’ve ever filmed!

The Head of the Cam 2025

Andy Southgate — Sat, 19 Apr 2025 10:39:56 GMT

The Head of the Cam

This year, I plan to record the Head of the Cam, something I haven’t done since 2014. Long story short, I now own a suitable camera, so there is no camera hire to worry about. So, if you see someone with a tripod on Grassy Corner, it’ll likely be me!

I’m also planning to experiment with video streaming with Omnistream. This might be more watchable when Bumps time comes around, so this is more of a technical try-out. I’ll add whatever links I have to this page when I have them, in case you want to drop in.

Livestream links

If it works as planned, there should be a livestream for each division:

Division 1: https://youtube.com/live/8z5DYptWYko?feature=share [Update: this one worked]
Division 2: https://youtube.com/live/GPhOTYna0PA?feature=share [this just about worked]
Division 3: This didn’t work.
Division 4: This failed too.

But not to worry, the footage from the main camera is all good and it’s processing now.

Update

I’m uploading the footage as soon as the software finishes its processing magic for each one. The playlist link is a good place to start https://www.youtube.com/playlist?list=PL8qwRteVIPAZ-0VBOeVu6G85z07Dw0Uti. It’s worth switching to 4K if you’re on a big screen and YouTube doesn’t do it for you.

New to Bumps racing?

Andy Southgate — Sat, 12 Apr 2025 08:01:39 GMT

It’s what you do when you have lots of boats and a narrow river. All boats start at the same time and you catch the boat ahead to win. Want to see a bump? Here’s one on YouTube.

A farewell to Oarstack

Andy Southgate — Thu, 10 Apr 2025 22:52:33 GMT

In 2022 we said goodbye to Oarstack, with its separate videos for normal speed and slow motion and very purist lack of on-screen text. But it had a good run! Oarstack was created when the footage moved to YouTube in 2014. In the end it had all sorts of automation to get the footage uploaded during the days of the events. It could do things that the 2025 system still can’t, like generate a custom description for each video. It would spend hours uploading to YouTube overnight - a key feature back in the days of slow broadband. Playlists were king, and used to tie the normal and slow motion footage together.

YouTube does downgrade the quality of footage it shows if it hasn’t been watched for, well, a decade, but I still have the originals! Here’s a sample below - it’s YouTube equivalent is Cauis M1 from the Head of the Cam 2014.

For this event I could use the burst feature of Sony’s NEX-FS700 to record at 120fps for up to 16 seconds. The camera would then take three times the capture duration to write it to memory, so with luck would just be ready in time for the next crew. Alas that wouldn’t work for the Bumps races, which need continuous capture for a couple of minutes.

Here’s what the front page of www.oarstack.com looked like on the day of retirement:

and here’s a copy of the content:

Welcome to Oarstack! Please choose a destination:

Footage from the Cambridge Town Bumps 2022 is on the YouTube channel.

Footage from the Cambridge May Bumps 2022 is on the YouTube channel.

Footage from the Cambridge Town Bumps 2021.

Extracting photos from the Cambridge June Eights Regatta 2021 footage.

Footage from the Cambridge June Eights Regatta 2021.

Footage from the Cambridge Town Bumps 2019.

Footage from the Cambridge May Bumps 2019.

Footage from the Cambridge May Bumps 2018.

Footage from the Cambridge May Bumps 2017.

Thursday Footage from the Cambridge May Bumps 2016.

Wednesday Footage from the Cambridge May Bumps 2016.

2015 footage from Wednesday and Thursday.

Oarstack analysis, also your source for high-quality downloads.

The 2014 highlights reel – start here for a taster.

Recent footage – find what you need quickly.

Oarstack on YouTube for 2016, 2015 and 2014 – the Oarstack YouTube channels.

Extracting a photo from Oarstack video – a guide.

Oarstack on Facebook – Like this page to get updates.

Oarstack on Twitter.

Footage from the Cambridge Town Bumps 2021

Andy Southgate — Tue, 20 Jul 2021 13:32:17 GMT

Slightly different format for this year, since YouTube upload limits will mean footage appears there only slowly. So, footage from the Cambridge Town Bumps 2021 is appearing here first:

https://muse.ai/southgate/collections/vUoFKMo: Up to date footage on muse.ai.

https://www.youtube.com/channel/UCjim1mqCkCQR0slOnqM62lA/search?query=Cambridge%20Town%20Bumps%202021: The usual YouTube link, but you’ll mostly see older events.

More should appear over the next few days.

The post Footage from the Cambridge Town Bumps 2021 appeared first on Oarstack.

Extracting photos from the Cambridge June Eights Regatta 2021 Footage

Andy Southgate — Thu, 24 Jun 2021 08:44:14 GMT

The original high bitrate files used for the uploads to YouTube are available here:

https://1drv.ms/u/s!Aod5U9_SG36jkrhVwBBKh1hLKnaYNg?e=wXXtdG

The OneDrive site won’t necessarily play them, but you can download. Applications like the Photos app in Windows 10 can then save frames as photos (Edit & Create->Save Photos). If you want to then upload the photos to Jet Photographic (https://jetphotographic.com/, Upload YOUR images here) and get mounted prints made up then that is absolutely fine by me.

The post Extracting photos from the Cambridge June Eights Regatta 2021 Footage appeared first on Oarstack.